In the manufacturing of automotive vehicles, it is customary to preassemble components and to marry or install them to the vehicle chassis from the underside of the vehicle. Typically, the vehicle chassis is conveyed overhead on a moving conveyer, while the components to be married to the chassis are supported and transported underneath the vehicle chassis by an AGV which rides around in a track or on the floor of the assembly plant. The AGV includes a fixture for supporting the components so that when the components are lined up beneath the vehicle chassis, the fixture and components can be lifted into place and fastened to the chassis. Once the components are secured to the chassis, the empty fixture is lowered back down and the AGV resumes its position at the beginning of the loading and assembly process.
One challenge facing such an assembly process is the large number of vehicle model and feature combinations often produced in the same manufacturing facility. For instance, it is not uncommon for a single vehicle to offer various suspension, engine and transmission packages; each of which requires different fixture locating and nesting features in order to accommodate the different shapes and sizes of the various components. Oftentimes, a fixture will have some type of model-to-model changeover feature which allows a single AGV fixture to be used with a number of different models. One example of such a changeover feature is a flip or pivot down detail, which enables the locating and nesting features to either be manually or automatically rotated in and out of a work position.
Although certain types of fixtures, such as those mentioned above, have been successfully used to accommodate a wide variety of vehicle component combinations, the fixtures with all of their various locating and nesting features can become quite complex and complicated to operate. For instance, many of the locating and nesting features must be flipped in a particular sequence in order to avoid interferences with other details. This is particularly true with more congested fixtures. Furthermore, these types of fixtures are oftentimes not scaleable, in that it is economically and logistically prohibitive to retrofit the fixture to accommodate additional models and feature combinations.